Nonslipping roller supports for a rotatable ring

ABSTRACT

An apparatus for supporting and guiding a rotatable ring of polygonal cross section comprising at least one V-type shaped roller-supporting means and at least two other roller-supporting means angularly spaced around the circumference of the ring. The one V-type shaped roller means has two radially spaced nonslipping pure rolling points of contact between its conical flanges and the ring so that a straight line through these two points intersects the axis of the roller means on the axis of rotation of the ring. One or more of the roller means may be driven to rotate the ring. A plurality of concentric rings may be employed and may be commonly or separately driven at either the same angular velocity or at different angular velocities. The rings may be hollow for the conduction of electricity and/or fluids to stations mounted on the ring or rings, and the ring may have lugs or flanges for operating limit switches, cams and/or the engagement of braking means.

United States Patent 72] Inventor Donald L. Tillman 805 West Wayne St., Maumee, Ohio 43537 [21] Appl. No. 873,180 [22] Filed Nov. 3, 1969 [45] Patented Nov.30,197l

[54] NONSLIPPING ROLLER SUPPORTS FOR A Primary Examiner-Richard E. Aegerter AnorneyHugh Adam Kirk ABSTRACT: An apparatus for supporting and guiding a rotatable ring of polygonal cross section comprising at least one V-type shaped roller-supporting means and at least two other roller-supporting means angularly spaced around the circumference of the ring. The one V-type shaped roller means has two radially spaced nonslipping pure rolling points of contact between its conical flanges and the ring so that a straight line through these two points intersects the axis of the roller means on the axis of rotation of the ring. One or more of the roller means may be driven to rotate the ring. A plurality of concentric rings may be employed and may be commonly or separately driven at either the same angular velocity or at different angular velocities. The rings may be hollow for the conduction of electricity and/or fluids to stations mounted on the ring or rings. and the ring may have lugs or flanges for operating limit switches, cams and/or the engagement of braking means.

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A T A FIG. 9 DON LD L ILLM N m! /l I ATTORNEY PATENTEnunv 30 1911 3. 623 599 sum 5 UF 6 IN VEN'H )R. DONALD L. TILLMAN ATTORNEY NONSLIPPING ROLLER SUPPORTS FOR A ROTATABLE RING BACKGROUND OF THE INVENTION l. Field of The Invention This invention relates to means for frictionally rotating an article-supporting conveyor ring, and is particularly directed to the rolls which support, guide, and drive the ring by a pure rolling nonslipping movement.

2. Description of The Prior Art Although rolls which support and rotate annular platforms or rings are known, none show two nonslipping points of roller contact between one roller means and a ring.

SUMMARY OF THE INVENTION A. Gist of The Invention Generally speaking, this invention embodies a plurality of supporting roll mechanisms for an article-supporting rotatable ring or keel having a polygonal circular or elliptical cross section. The V-shaped configuration of at least one and preferably all of the rolls each has facing conical flanges of different apex angles. The other rolls, if any, may be cylindrical supporting and guiding rolls, and usually are not driven. However, if one roll is driven it is preferably the V-shaped supporting roll. Between the conical flanges of the V-shaped roll the ring is wedged and supported so that its cross section provides two nonslipping pure rolling stable points of contact with the flanges of that roll. One point of contact is at a radius greater than the mean radius of the ring and the other point of contact is at a radius less than the mean radius of the ring. These two points of contact must lie on a straight line which intersects the axis of the roll on the axis of rotation ofthe ring in order to be nonslipping with respect to the ring.

The roll mechanisms each comprise a horizontally disposed fixed base upon which the ring-supporting rolls are rotatably mounted on axes radially of the ring, but not necessarily horizontally. These fixed base locations aid in maintaining the ring circular and keep it from becoming distorted, particularly for large rings of several meters in diameter since the rings need not have a central shaft or central bearings. The rolls may be idler rolls or they may be driven by a gear reduction unit and motor assembly which also may be mounted on the fixed base.

The ring may be hollow and used as a conductor for supplying fluids to work stations mounted on the ring, such as supplying vacuum to a molding station, conducting a heating or cooling medium including one for controlling the expansion of the ring itself, or for supplying hydraulic pressure for power to a station or stations on the ring. Also electrical conductors may be mounted in or on the ring for supplying electrical power to stations on the ring, Cams and/or stops may be mounted on the ring for controlling its rotation by means of limit switches, and a flange may be mounted on the ring for engagement by a caliper or disk-type braking jaw for stopping the rotation of the ring. Furthermore, two or more concentric article-supporting rings may be mounted on the type of roll mechanisms of this invention, and each may be rotated at the same angular speed, or the rings may be rotated at different angular speeds either from a common drive means or from independent drive means.

Thus the rotatable ring conveyor of this invention may be provided with platforms or work stations to be used industrially, such as in factories or foundries for supporting molds during their construction or assembly and/or during forming or casting operations, or for multiple station machines such as vacuum-molding machines, machine tools, or other material operating equipment in which the power for the equipment at the stations on the ring may be conducted through the ring of the conveyor. Also the ring conveyor and supporting rollers of this invention may be used for large circular rotating restaurants in towers, or for amusement devices as merry-goarounds and similar or other platforms, or domes for telescopes or for large telescopes themselves such as radio telescopes and radar antenna, or for the handling of food in restaurants, or for slewing rings on large power shovels, or for indexing units, etc. By driving such mechanisms on the nonslipping rollers of this invention, it is possible to maintain the circular configuration of the rings having radii of 8 feet or more to within a small fraction of an inch of their perfect circumferences. Furthermore the speed reduction usually required to drive such a ring by a shaft through its axis is usually over a hundred times greater than that required for driving the roller means of this invention, which results in a material savings in the expense of speed-reduction mechanisms and power.

B. Objects and Advantages Accordingly, it is an object of this invention to provide a simple, efficient, effective, economic, durable, steady, smoothly operating, accurate, and quiet circular conveyor requiring no center shaft or bearings.

Another object is to provide such a conveyor supported by two points of contact on at least one of a plurality of fixedly located rolls, which rolls maintain the circularity of the conveyor and have nonslipping rolling contact with it at all times.

Another object is to drive one or more of such supporting rolls by a relatively low-energy standard type of motive power source which does not require a high degree of speed reduction.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features, objects and advantages and a manner of attaining them are described more specifically below by reference to embodiments of this invention shown in the accompanying drawings, wherein:

FIG. 1 is a schematic perspective view of one embodiment of this invention showing an article-supporting ring supported by three roller means;

FIG. 2 is a fragmentary diagrammatic cross-sectional view, taken substantially along lines 22 of FIG. 1 showing the relationship between a driving roll and the article-supporting ring;

FIG. 3 is a view similar to FIG. 2 showing the relationship between the ring and the roll when the axis of the roll is not perpendicular to the axis of rotation of the ring;

FIGS. 4 and 5 are fragmentary diagrammatic views similar to FIGS. 2 or 3 of rings of different cross sections being supported by the roller means of this invention;

FIG. 6 is an enlarged cross-sectional view of the ring and one of the other supporting roll mechanisms taken along the line 66 in FIG. I, which roll mechanisms may be used in cooperation with the mechanism shown in FIG. 2;

FIG. 7 is a plan view of a device similar to that shown in FIG. 1 but for use in a vacuum-molding device in which the vacuum to the molds is conducted through the ring that is entirely supported by the V-shaped rolls of this invention, and which ring also is provided with stops for operating limit switches;

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7 showing two of the V-shaped supporting rolls and the drive for one of them, as well as valve means operated by the rotation of the ring into a given position for controlling the connection of the vacuum at a given station;

FIG. 9 is an enlarged sectional view of the driving roller for the ring showing friction-increasing pads on the conical surfaces of the flanges of the roller;

FIG. 10 is an enlarged sectional view through line I0I0 of FIG. 7 showing a cam or lever-operating finger or stop mounted on the ring for operating a limit switch;

FIG. 11 is a schematic perspective view of another embodiment of this invention showing two concentric article-supporting rings supported by three roller means, in which both rings are driven at the same angular velocity by a single pair of commonly driven different V-shaped roller means according to this invention;

FIG. 12 is an enlarged radial sectional view taken substantially along lines 12-12 of FIG. 11 showing the common drive of the pair of roller means constructed in accordance with this invention, and the brackets for supporting a mold by both the rings, including the relative geometry of the supporting rolls and rings;

FIG. 13 is a diagrammatic view similar to FIG. 12 showing the geometrical relationship of the points of contact when the two rings are driven at different annular speeds; and

FIG. 14 is an enlarged sectional view which may be taken along line I4 14 of FIG. 11 showing one of the rollers and a flange on one of the rings for engagement with a disk brake to insure accurate stopping of that ring at a given location.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A. Geometry of Ring and Rolls Before describing any specific embodiments of this invention the geometric theory of this invention will first be described with reference to FIGS. 1 through 6, wherein FIG. 1 schematically discloses a circular rotatable ring mounted on at least three equally angularly or circumferentially spaced roll assemblies and 40, the former assembly 30 of which is provided with a V-shaped roll 50 of this invention (see also FIG. 2), and may include a driving means. The other two assemblies act merely to support the ring 20 for rotation and may include idler and guide rolls such as rolls 60 and 65, respectively, (see also FIG. 6). Each of these roll assemblies 30 and 40 has a platform or base 32 or 42, respectively, which is preferably anchored to an immovable frame or floor and have mounted thereon the supporting rollers 50 and 60, respectively, the axes of which all converge to meet along the rotational axis or center line 21 of the ring 20 so that they are all mounted radially with respect to the ring 20. More specifically these rollers 50 and 60 may be either rotatably mounted on or fixedly secured to axles aligned with these radial axes and which axles may be rotatably supported in or secured to brackets such as 34 and 44 fixedly attached to their respective bases 32 and 42. If the ring 20 is to be rotated or driven, one of the axles of one of the rollers namely axle 36 for the roller 50 mounted on the assembly 30, may be extended to a driving mechanism 38 which may comprise an electric motor and gear reduction device which may be controlled in various manners as will be described later.

Referring more specifically to the geometry of the roller 50 and the cross section of the ring 20 of the roll assembly 32 as shown in FIG. I, reference is now had to FIGS. 2 through 5. The roller 50 shown in FIG. 2 has substantially a V-shaped or a pair of conical end flanges SI and 52 which have angular tapers that contact the ring 20, which in this instance is shown to be of circular cross section, at two separate points 53 and 54. These points 53 and 54 are tangent to the outside surface of the ring 20 and are along a line 55 which intersects the center line or axis 56 of the roller 50 at a point 57 which lies on the axis of rotation or center line 21 of the ring 20. In order to insure that the points 53 and 54 of contact of the ring 20 with the roller 50 will not slip relative to each other because of their different radii from the center line 21, the angular taper of the conical flanges 51 and 52 are correspondingly different and are so made that the point 53, having a radius greater than the mean radius of the ring 20, has a steeper tapered conical flange 51 than the taper of the conical flange 52, and thus will contact its flange 51 at a greater radial distance with respect to the axis 56 of the roller 50 than the point 54 to compensate for the differences in radii of these points 53 and 54 from the axis of rotation 21 of the ring 20. Under these conditions there is no slipping, only rolling contact between the surface of the ring 20 and the supporting roller 50, and all of the other V- shaped rollers of this invention are correspondingly so designed depending of course upon the cross sectional configuration of the ring 20.

It is not necessary, however, that the axis 56 of the roller 50 be horizontal or in a plane parallel to the ring 20, in that it may bet an angle thereto as shown in FIG. 3 for a roll 70 having an axis 76 wherein the same criterion for the axis 76 and line 75 4 holds, namely that they intersect at the point 77 on the axis 2I of the ring 20. This roller 70, however, has different angularshaped flanges II and 72 from that of flanges 51 and 52 to correspond to the different angular position with relation to the geometry of the roll and the ring.

Furthermore, it is not necessary that the cross-sectional area of the ring 20 be a circular tube or a bar as shown in FIGS. 1, 2 and 3, but it may have a rectangular cross section as the ring 22 shown in FIG. 4, or an elipse as the ring 24 shown in FIG. 5. However, the corresponding flanges on the rollers 80 and 90, respectively, for supporting these different crosssectional configuration rings 22 and 24, have flanges 81, 82 and 91, 92 of different conical angles so that their points of contact 83, 84 and 93, 94 respectively, lie on a straight line 85, 95 which intersects the center line 86, 96 of the rollers 80 and 90 at the axis 21 of the rings 22 and 24, respectively.

Although the other supporting roller mechanisms 40 (see FIG. 1) may have similar rollers 50, such is not necessary, and one or more of them may comprise a plain cylindrical roller 60 as shown in FIG. 6, which preferably is associated with one or more vertical axis cylindrical guide rollers 65 for the outer and inner circumference of the ring 20, which guide rollers 65 are mounted on vertical shafts 66 preferably also fastened at their lower ends to the bases 42.

B. A Single-ring Fluid-carrying Conveyor Referring now specifically to the embodiments shown in FIGS. 7 through 10, there is disclosed a single tubular ring I00 of circular cross section mounted on three equally angularly spaced supporting roller assemblies comprising a driven roller assembly I20 and two idler roller assemblies 140. Each of these roller assemblies comprises a double conical flange or V-shaped type roller 150 of the same shape as shown in more detail in FIG. 9.

In this embodiment there are welded to the top of the ring 100 four equally angularly spaced posts 102 supporting angle brackets I04 welded across the intersecting corners of a pair of parallel intersecting crossbars I06 supporting at their four outer ends outside the ring 100 four separate equally angularly spaced rectangular platforms M0 for vacuum-molding sta tions. Each of these platforms is connected by vacuum duct lines I I2 extending to the top center of the hollow tubular ring 100. This tubular ring is supplied with vacuum from a central axial supply duct 1 I4 (see FIG. 8) having a swiveljoint connection [IS with a radial rotating duct 116 connected to the top of the tubular ring I00. If desired, the duct I16 may be provided with a flexible section 117 to compensate for any noncircularity in the ring I00. Each of the radial ducts 112 to the stations or platforms 110 may be provided with valve means 118 (see FIG. 8), which valve means 118 may be operated by a cam means or operator for controlling the vacuum supply at predetermined locations around the ring 100, such as the operator I19 mounted on the roller assembly base 120.

The rollers as shown in FIG. 9 for the driving mechanism shown in FIGS. 7 and 8 comprises two conical flanges l5] and 152 with resilient or plastic faces or inserts 155 to increase the friction at the two points I53 and I54 of rolling contact with the outside surface of the ring 100. These flanges 151 and 152 are each shown keyed to a shaft 158, which shaft may be driven by a sprocket wheel connected by a sprocket chain 162 to a gear reduction mechanism 164 driven by an electric motor 166. The ends of the shafts 158 for each of the rollers 150 are journaled in brackets I68 mounted on the pedestal or base 120 or 140. Also, if desired there may be provided limit switches at predetermined locations around the ring 100 for controlling the operation of the motor I66, which switches may be operated by stops or cam means 172 (see FIGS. 7 and 10) attached to the ring 100.

Thus a hollow ring I00 may be used for transmitting vacuum or fluids to different work stations, or the ring 100 may have circulated therein a liquid to control its temperature to prevent its expansion and contraction, particularly in the cases of large rings or rings operating platforms which pass through furnaces. Furthermore, the tubular ring 100 may be used for housing electrical conductors to supply electricity to power and/or control machines or other devices located on the platforms 110.

C. Multiring Assemblies Referring now to FIG. 11 there is shown schematically a pair of concentric rings 200 and 210 which are supported by three equally angularly space driven and idler supporting roller mechanisms 230 and 240, respectively, each having a pair of rollers 250 and 260. If each of these pairs is identical and have flanges tapering according to this invention, the two rollers of each pair may be keyed to the same shafts 270 which extend radially from the common center of both rings 200 and 210. The driven pair of rollers 250 and 260 of mechanism 230 may have its shaft 270 connected to a driving means 258 which also may be mounted on the same base 232 that supports its pair of rollers. The idler pairs of rollers 250 and 260 of mechanism 240 are mounted on their bases 242.

In FIG. 12 there is shown mounted to the top of each ring 200 and 210 vertical supporting means 202 and 212, respectively, between or upon which may be mounted a mold M or other means or platform to be conveyed. If desired, one of the vertical supporting means may be provided with a flexible joint to compensate for any noncircularity and/or nonconcentricity of the rings 200 and 210, such as the joint 214 on the means or leg 212 shown in FIG. 12.

Although the embodiment in FIG. 11 shows both rolls or rollers 250 and 260 of each mechanism connected to the same shaft 270, a flexible drive connection 270' (see FIG. 12) may be used to interconnect the rollers 250 and 260. Also, if desired the rollers 250 and 260 may be separately driven, either at the same speed or at different speeds, in which latter case the rings 200 and 210 would be driven at different angular speeds and then would not be connected together such as by a mold or as shown in FIG. 12. In either case, the taper of the flanges 251 and 252 of roller 250 must have steeper slopes than the flanges 261 and 262 of the roller 260, so that the two points 253 and 254 of contact between the roller 250 and the ring 200 lies in the same straight line 265 as the two points 263 and 264 of contact of the roller 260 and the ring 210, which line 265 also intersects the common center line 266 of both the rollers 250 and 260 at the point 267 which lies on the common center line 201 of both rings 200 and 210.

On the other hand, another embodiment of this invention may comprise two concentric rings 300 and 310 which may be driven at the same or at relatively different speeds (see FIG. 13 The rolls 350 and 360 may be keyed to the same shaft and driven from a common drive such as shown in FIG. 12 or the rolls 350 and 360 may be independently driven from separate drive motors (not shown). In this case the V-shaped supporting rollers 350 and 360, respectively, of each ring 300 and 310 have different configurations than those shown in FIG. 12, but the two points of contact of each roller 350 and 360 with its corresponding ring must correspond to the geometry shown and described in FIG. 2 above. Namely, the flanges 351 and 352 of the roller 350 must have its points 353 and 354 of contact with ring 300 lie on the straight line 355, while the flanges 361 and 362 of the roller 360 have a different straight line 365 through its points 363 and 364 of contact with the ring 310, but both straight lines 355 and 365 meet at a common point 367 at the intersection of the center line 366 of both the rollers on the common center line 301 of the rings 300 and 310. In this case, if the rollers 350 and 360 are mounted together and driven at the same speed, the rings 300 and 310 will be driven at different angular speeds. Thus if the rollers 350 and 360 are separately driven at different speeds, then the rings 300 and 310 may be driven either at the same or different angular speeds depending upon the geometry of the points of contact and the center lines of the rollers and rings.

Accordingly any inner ring may be rotated faster, slower or at the same angular speed as it's neighbor and may or may not be keyed to a common drive shaft.

' driving means for said one roller for Furthermore there may be provided on any one of the rings 100, 200, or 210, 300, or 310 of this invention an outwardly extending flange which may act as a shoe against which a fixed disk or caliper-type brake clamp may engage, such as the flange 206 and brake 208 shown for the ring 200 in FIG. 14, to insure accurate stopping of the ring at a desired location.

It is to be understood that one or more of the different features disclosed in the different embodiments of this invention may be adapted to another embodiment without departing from the scope of this invention, and that more rings than two may be provided, and that the diameter of the rings can be extended within any physical or practical limits. Furthermore it is to be understood that more than three roller assemblies may be provided for supporting the rings.

Iclaim:

l. A ring rotatable about its axis comprising at least three angularly spaced roller means for supporting said ring, at least one of which rollers has a pair of spaced converging conically surfaced flanges which surfaces contact said ring at two points radially spaced with respect to the center of said ring and through which points a straight line intersects the axis of said one roller means on said axis of rotation of said ring.

2. A ring according to claim 1 including means for driving at least one of said roller means to rotate said ring.

3. A ring according to claim 1 including means for supporting work stations on said ring.

4. A ring according to claim 1 including cam means on said ring and control switches located around said ring cooperable with said cam means.

5. A ring according to claim 1 including flange means on said ring and brake-type jaws located at least at one position along the circumference of said ring adjacent to said flange means for engaging said flange means.

6. A ring according to claim 1 wherein another of said roller means comprises a supporting cylindrical roller.

7. A ring according to claim 1 including a guiding cylindrical roller engageable with said ring.

8 A ring according to claim 1 wherein all of said roller means have a pair of flanges which contact said ring as said one roller means.

9. A plurality of concentric rings each having supporting roller means according to claim 1.

10, A plurality of concentric rings according to claim 9 wherein said one roller means for each ring of said plurality of rings has its two points of contact in the same straight line with the two points of contact of each of the other said one roller means.

11. A plurality of concentric rings according to claim 9 wherein said one roller means for each said ring has its two points of contact in different straight lines which intersect at a common point on said axis of rotation of said rings.

12. A circular conveyor comprising:

A. a ring rail having a center axis,

B. an article-supporting means connected to said rail, and

C. at least three circumferentially spaced supporting rollers for said rail, at least one of said rollers having a pair of spaced converging conically surfaced flanges which provide two points of contact with said rail radially spaced with respect to the center of said ring rail, said points of contact being on a straight line which intersects the axis of said roller at the axis of said ring whereby each of which points has the same angular velocity with said rail when said rail is rotating about its said axis.

13. A conveyor according to claim 12 including means for driving said one roller to rotate said conveyor.

14. A conveyor according to claim 12 including two concentric rings mounted on separate rollers.

15. A conveyor according to claim 14 including a common driving means for said one roller for each ring for rotating both said rings.

16. A conveyor according to claim 14 including different each said ring for rotating said rings.

17. A conveyor according to claim 12 wherein said one roller comprises a pair of conical flanges which have different apex angles.

18. A conveyor according to claim 17 wherein said conical flanges have friction-engaging means to reduce slipping at said points of contact between said ring and said flanges. 

1. A ring rotatable about its axis comprising at least three angularly spaced roller means for supporting said ring, at least one of which rollers has a pair of spaced converging conically surfaced flanges which surfaces contact said ring at two points radially spaced with respect to the center of said ring and through which points a straight line intersects the axis of said one roller means on said axis of rotation of said ring.
 2. A ring according to claim 1 including means for driving at least one of said roller means to rotate said ring.
 3. A ring according to claim 1 including means for supporting work stations on said ring.
 4. A ring according to claim 1 including cam means on said ring and control switches located around said ring cooperable with said cam means.
 5. A ring according to claim 1 including flange means on said ring and brake-type jaws located at least at one position aLong the circumference of said ring adjacent to said flange means for engaging said flange means.
 6. A ring according to claim 1 wherein another of said roller means comprises a supporting cylindrical roller.
 7. A ring according to claim 1 including a guiding cylindrical roller engageable with said ring.
 8. A ring according to claim 1 wherein all of said roller means have a pair of flanges which contact said ring as said one roller means.
 9. A plurality of concentric rings each having supporting roller means according to claim
 1. 10. A plurality of concentric rings according to claim 9 wherein said one roller means for each ring of said plurality of rings has its two points of contact in the same straight line with the two points of contact of each of the other said one roller means.
 11. A plurality of concentric rings according to claim 9 wherein said one roller means for each said ring has its two points of contact in different straight lines which intersect at a common point on said axis of rotation of said rings.
 12. A circular conveyor comprising: A. a ring rail having a center axis, B. an article-supporting means connected to said rail, and C. at least three circumferentially spaced supporting rollers for said rail, at least one of said rollers having a pair of spaced converging conically surfaced flanges which provide two points of contact with said rail radially spaced with respect to the center of said ring rail, said points of contact being on a straight line which intersects the axis of said roller at the axis of said ring whereby each of which points has the same angular velocity with said rail when said rail is rotating about its said axis.
 13. A conveyor according to claim 12 including means for driving said one roller to rotate said conveyor.
 14. A conveyor according to claim 12 including two concentric rings mounted on separate rollers.
 15. A conveyor according to claim 14 including a common driving means for said one roller for each ring for rotating both said rings.
 16. A conveyor according to claim 14 including different driving means for said one roller for each said ring for rotating said rings.
 17. A conveyor according to claim 12 wherein said one roller comprises a pair of conical flanges which have different apex angles.
 18. A conveyor according to claim 17 wherein said conical flanges have friction-engaging means to reduce slipping at said points of contact between said ring and said flanges. 